1. Field of the Invention
The present invention relates to a vehicle washing system and, more particularly, to such a system which is provided with the capability of supplying a chemical through the existing high pressure pumping system under low pressure.
2. Description of the Prior Art
In order to preserve the quality and condition of the body of an automobile it is advisable to thoroughly wash and clean any dirt thereon to prevent the retention of moisture therein which aids in the formation of rust. Many individuals take their vehicles to self-service car washes which are coin operated and provide high-pressure application of soap solution or water to rinse the automobile. Many of these car wash systems have added the additional features of supplying not only soap and water but also liquid wax, engine degreaser solvent and whitewall cleaner. These additional chemical products are dispensed through the normal boom and wand assemblies, however, these chemicals are much too expensive to dispense at the high-pressure pumping rate of three or four gallons per minute. It is therefore advisable to deliver these chemicals at a lower pressure which necessitates the addition of a separate low-pressure pumping system which adds to the cost of the construction and maintenance of the auto wash system.
Two basic methods have been developed in order to dispense a chemical at low-pressure and both involve the addition of a separate pumping station, which is connected electrically to a high-pressure pumping assembly, and is connected through a separate plumbing line to each individual bay and the boom and wand assemblies. At the boom assembly an electric solenoid and check valve assembly must be installed on the alternate supply line for the low-pressure solution. This basic system has several design deficiencies in that it requires electrical service to the boom assembly where none was required before and it requires a separate plumbing line from the extra pumping station to each bay. Further, the extra plumbing line cannot be prevented from freezing in the winter time by the normal freezing protection of a "weep" system that is utilized in the high-pressure line. To prevent freezing this line is normally wrapped with heat tape or is supplied with a forced air heating apparatus.
The second type of low-pressure system which is currently being utilized uses basically the same features as the first type of system as described above with exception of the method by which to prevent the line from freezing. In the second system, the low-pressure solution is recirculated in a closed loop plumbing line from the additional pumping station to the boom and wand assembly and then back to the pumping station. The chemical remains in circulation at all times and when a low-pressure chemical is chosen by the operator, the valve at the boom assembly is merely opened which allows the alternate supply line to supply its product to the wand. This system also has all the disadvantages of the first system with the additional disadvantage of having an extra line from the extra pumping station to the boom and wand assembly to provide the closed loop. It does not appear that there is a simple system which may be easily added to an existing auto wash system and which can provide a low-pressure application of a liquid through an existing high-pressure system without the addition of an extra pumping station and additional supply lines.